Processing a data packet received over control plane in congestion scenario

ABSTRACT

Certain aspects of the present disclosure relate to methods and apparatus for communicating data between a user-equipment and network entity. For example, certain aspects of the present disclosure provide a method for wireless communication. The method generally includes receiving a message comprising a data packet from a user equipment (UE) during a communication session, and detecting whether the data packet is the last data packet for transmission or reception by the UE during the communication session. In certain aspects, the method also includes determining whether to process or discard the data packet based on the detection and whether a backoff timer is to be sent to the UE, and processing or discarding the data packet based on the determination.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 15/702,429, filed Sep. 12, 2017, which claims benefit of priority toProvisional Application No. 62/402,289, filed Sep. 30, 2016, which isexpressly incorporated herein by reference in its entirety.

BACKGROUND Field of the Disclosure

The present disclosure relates generally to wireless communication, andmore particularly, to methods and apparatus for communicating datapackets.

Description of Related Art

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includecode division multiple access (CDMA) systems, time division multipleaccess (TDMA) systems, frequency division multiple access (FDMA)systems, orthogonal frequency division multiple access (OFDMA) systems,single-carrier frequency divisional multiple access (SC-FDMA) systems,and time division synchronous code division multiple access (TD-SCDMA)systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by ThirdGeneration Partnership Project (3GPP). However, as the demand for mobilebroadband access continues to increase, there exists a need for furtherimprovements in LTE technology. Preferably, these improvements should beapplicable to other multi-access technologies and the telecommunicationstandards that employ these technologies.

SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “DETAILED DESCRIPTION” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

The present disclosure relates generally to wireless communication, andmore particularly, to communication of data packets between a userequipment (UE) and a network node.

Certain aspects of the present disclosure provide a method for wirelesscommunication by a network node. The method generally includes receivinga message comprising a data packet from a UE during a communicationsession, detecting whether the data packet is the last data packet fortransmission or reception by the UE during the communication session,determining whether to process or discard the data packet based on thedetection and whether a backoff timer is to be sent to the UE, andprocessing or discarding the data packet based on the determination.

Certain aspects of the present disclosure provide a method for wirelesscommunications by a UE. The method generally includes transmitting adata packet to a network node during a communication session, andreceiving a message including an indication of a back-off timer from thenetwork node in response to the data packet. In certain aspects, themethod also includes determining whether the data packet was processedby the network node based on whether the message comprises an acceptmessage or a reject message, and indicating to an upper layer of the UEwhether the data packet was processed based on the determination.

Certain aspects of the present disclosure provide an apparatus forwireless communication by a network node. The apparatus generallyincludes means for receiving a message comprising a data packet from aUE during a communication session, and means for detecting whether thedata packet is the last data packet for transmission or reception by theUE during the communication session. In certain aspects, apparatus alsoincludes means for determining whether to process or discard the datapacket based on the detection and whether a backoff timer is to be sentto the UE, and means for processing or discarding the data packet basedon the determination.

Certain aspects of the present disclosure provide an apparatus forwireless communication by a UE. The apparatus generally includes meansfor transmitting a data packet to a network node during a communicationsession, and means for receiving a message including an indication of aback-off timer from the network node in response to the data packet. Incertain aspects, the apparatus may also include means for determiningwhether the data packet was processed by the network node based onwhether the message comprises an accept message or a reject message, andmeans for indicating to an upper layer of the UE whether the data packetwas processed based on the determination.

Certain aspects of the present disclosure provide a computer-readablemedium having instructions stored thereon to cause a network node toreceive a message comprising a data packet from a UE during acommunication session, detect whether the data packet is the last datapacket for transmission or reception by the UE during the communicationsession, determine whether to process or discard the data packet basedon the detection and whether a backoff timer is to be sent to the UE,and process or discard the data packet based on the determination.

Certain aspects of the present disclosure provide a computer-readablemedium having instructions stored thereon to cause a UE to transmit adata packet to a network node during a communication session, andreceive a message including an indication of a back-off timer from thenetwork node in response to the data packet. In certain aspects, theinstructions cause the UE to determine whether the data packet wasprocessed by the network node based on whether the message comprises anaccept message or a reject message, and indicate to an upper layer ofthe UE whether the data packet was processed based on the determination.

Certain aspects of the present disclosure provide an apparatus forwireless communication by a network node. The apparatus generallyincludes a receiver configured to receive a message comprising a datapacket from a UE during a communication session. The apparatus may alsoinclude a processing system configured to detect whether the data packetis the last data packet for transmission or reception by the UE duringthe communication session, determine whether to process or discard thedata packet based on the detection and whether a backoff timer is to besent to the UE, and process or discard the data packet based on thedetermination.

Certain aspects of the present disclosure provide an apparatus methodfor wireless communications by a UE. The apparatus generally includes atransmitter configured to transmit a data packet to a network nodeduring a communication session, and a receiver configured to receive amessage including an indication of a back-off timer from the networknode in response to the data packet. In certain aspects, the apparatusalso includes a processing system configured to determine whether thedata packet was processed by the network node based on whether themessage comprises an accept message or a reject message, and indicate toan upper layer of the UE whether the data packet was processed based onthe determination.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. The appended drawingsillustrate only certain typical aspects of this disclosure, however, andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects.

FIG. 1 is a diagram illustrating an example of a network architecture.

FIG. 2 is a diagram illustrating an example of an access network.

FIG. 3 is a diagram illustrating an example of a DL frame structure inLTE.

FIG. 4 is a diagram illustrating an example of an UL frame structure inLTE.

FIG. 5 is a diagram illustrating an example of a radio protocolarchitecture for the user and control plane.

FIG. 6 is a diagram illustrating an example of an evolved Node B anduser equipment in an access network, in accordance with certain aspectsof the disclosure.

FIG. 7 illustrates example operations for communicating control planedata back-off timer at registration, in accordance with certain aspectsof the present disclosure.

FIG. 8 illustrates example operations for wireless communication by anetwork node, in accordance with certain aspects of the presentdisclosure.

FIG. 9 illustrates example operations for wireless communication by auser-equipment (UE), in accordance with certain aspects of the presentdisclosure.

FIG. 10 illustrates operations for communicating control plane servicerequest and control plane data back-off timer, in accordance withcertain aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Certain aspects of the present disclosure provide techniques forhandling data communication to a network while the network isoverloaded. For example, in certain aspects, an MME may be configured todetermine whether to process or discard a data packet received from theUE based on whether the processing of the data packet would result infurther downlink and/or uplink communications. If further communicationsare to be expected and the MME has determined that the network isoverloaded, the MME may discard the data packet, in effect avoidingfurther downlink and/or uplink communications.

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim. The word “exemplary”is used herein to mean “serving as an example, instance, orillustration.” Any aspect described herein as “exemplary” is notnecessarily to be construed as preferred or advantageous over otheraspects.

Although particular aspects are described herein, many variations andpermutations of these aspects fall within the scope of the disclosure.Although some benefits and advantages of the preferred aspects arementioned, the scope of the disclosure is not intended to be limited toparticular benefits, uses, or objectives. Rather, aspects of thedisclosure are intended to be broadly applicable to different wirelesstechnologies, system configurations, networks, and transmissionprotocols, some of which are illustrated by way of example in thefigures and in the following description of the preferred aspects. Thedetailed description and drawings are merely illustrative of thedisclosure rather than limiting, the scope of the disclosure beingdefined by the appended claims and equivalents thereof.

The techniques described herein may be used for various wirelesscommunication networks such as Code Division Multiple Access (CDMA)networks, Time Division Multiple Access (TDMA) networks, FrequencyDivision Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA)networks, Single-Carrier FDMA (SC-FDMA) networks, etc. The terms“networks” and “systems” are often used interchangeably. A CDMA networkmay implement a radio technology such as Universal Terrestrial RadioAccess (UTRA), CDMA2000, etc. UTRA includes Wideband-CDMA (W-CDMA) andLow Chip Rate (LCR). CDMA2000 covers IS-2000, IS-95, and IS-856standards. A TDMA network may implement a radio technology such asGlobal System for Mobile Communications (GSM). An OFDMA network mayimplement a radio technology such as Evolved UTRA (E-UTRA), IEEE 802.11,IEEE 802.16, IEEE 802.20, Flash-OFDM®, etc. UTRA, E-UTRA, and GSM arepart of Universal Mobile Telecommunication System (UMTS). Long TermEvolution (LTE) is a release of UMTS that uses E-UTRA. It is designed tobetter support mobile broadband Internet access by improving spectralefficiency, lower costs, improve services, make use of new spectrum, andbetter integrate with other open standards using OFDMA on the downlink(DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output(MIMO) antenna technology. LTE, LTE-Advanced, and other releases of LTEare collectively referred to as LTE. UTRA, E-UTRA, GSM, UMTS, and LTEare described in documents from an organization named “3rd GenerationPartnership Project” (3GPP). CDMA2000 is described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thesecommunications networks are merely listed as examples of networks inwhich the techniques described in this disclosure may be applied;however, this disclosure is not limited to the above-describedcommunications network.

Single carrier frequency division multiple access (SC-FDMA) is atransmission technique that utilizes single carrier modulation at atransmitter side and frequency domain equalization at a receiver side.The SC-FDMA has similar performance and essentially the same overallcomplexity as those of OFDMA system. However, SC-FDMA signal has lowerpeak-to-average power ratio (PAPR) because of its inherent singlecarrier structure. The SC-FDMA has drawn attention, especially in theuplink (UL) communications where lower PAPR greatly benefits thewireless node in terms of transmit power efficiency.

Aspects of the present disclosure provide methods and apparatus for anuplink/downlink transmission design.

An access point (“AP”) may comprise, be implemented as, or known asNodeB, Radio Network Controller (“RNC”), eNodeB (eNB), Base StationController (“BSC”), Base Transceiver Station (“BTS”), Base Station(“BS”), Transceiver Function (“TF”), Radio Router, Radio Transceiver,Basic Service Set (“BSS”), Extended Service Set (“ESS”), Radio BaseStation (“RBS”), or some other terminology.

An access terminal (“AT”) may comprise, be implemented as, or be knownas an access terminal, a subscriber station, a subscriber unit, a mobilestation, a remote station, a remote terminal, a user terminal, a useragent, a user device, user equipment (UE), a user station, a wirelessnode, or some other terminology. In some implementations, an accessterminal may comprise a cellular telephone, a smart phone, a cordlesstelephone, a Session Initiation Protocol (“SIP”) phone, a wireless localloop (“WLL”) station, a personal digital assistant (“PDA”), a tablet, anetbook, a smartbook, an ultrabook, a handheld device having wirelessconnection capability, a Station (“STA”), or some other suitableprocessing device connected to a wireless modem. Accordingly, one ormore aspects taught herein may be incorporated into a phone (e.g., acellular phone, a smart phone), a computer (e.g., a desktop), a portablecommunication device, a portable computing device (e.g., a laptop, apersonal data assistant, a tablet, a netbook, a smartbook, anultrabook), wearable device (e.g., smart watch, smart/virtual realityglasses/googles, smart/virtual reality helmets/headsets, smart bracelet,smart wristband, smart ring, smart clothing, etc.), medical devices orequipment, biometric sensors/devices, an entertainment device (e.g.,music device, video device, satellite radio, gaming device, etc.), avehicular component or sensor, smart meters/sensors, industrialmanufacturing equipment, a positioning/navigation device (e.g., GPS,Beidou, Glonass, Galileo, terrestrial based, etc.), or any othersuitable device that is configured to communicate via a wireless orwired medium. In some aspects, the node is a wireless node. A wirelessnode may provide, for example, connectivity for or to a network (e.g., awide area network such as the Internet or a cellular network) via awired or wireless communication link. Some UEs may be consideredmachine-type communication (MTC) UEs, which may include remote devices,that may communicate with a base station, another remote device, or someother entity. Machine type communications (MTC) may refer tocommunication involving at least one remote device on at least one endof the communication and may include forms of data communication whichinvolve one or more entities that do not necessarily need humaninteraction. MTC UEs may include UEs that are capable of MTCcommunications with MTC servers and/or other MTC devices through PublicLand Mobile Networks (PLMN), for example. Examples of MTC devicesinclude sensors, meters, location tags, monitors, drones, robots/roboticdevices, etc. MTC UEs, as well as other types of UEs, may be implementedas NB-IoT (narrowband internet of things) devices.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later.

Example Wireless Communications System

FIG. 1 is a diagram illustrating a network architecture 100 in whichaspects of the present disclosure may be practiced. For example, UE 102may receive an uplink grant from an eNB 106 or 108 indicating one ormore tones within a resource block (RB) allocated to the UE fornarrowband communication. The UE 102 may then transmit using the one ormore tones indicated in the uplink grant.

The network architecture 100 may be referred to as an Evolved PacketSystem (EPS) 100. The EPS 100 may include one or more user equipment(UE) 102, an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)104, an Evolved Packet Core (EPC) 110, a Home Subscriber Server (HSS)120, and an Operator's IP Services 122. The EPS can interconnect withother access networks, but for simplicity those entities/interfaces arenot shown. Exemplary other access networks may include an IP MultimediaSubsystem (IMS) PDN, Internet PDN, Administrative PDN (e.g.,Provisioning PDN), carrier-specific PDN, operator-specific PDN, and/orGPS PDN. As shown, the EPS provides packet-switched services, however,as those skilled in the art will readily appreciate, the variousconcepts presented throughout this disclosure may be extended tonetworks providing circuit-switched services.

The network architecture 100 includes the evolved Node B (eNB) 106 andother eNBs 108. The eNB 106 provides user and control plane protocolterminations toward the UE 102. The eNB 106 may be connected to theother eNBs 108 via an X2 interface (e.g., backhaul). The eNB 106 mayalso be referred to as a base station, a base transceiver station, aradio base station, a radio transceiver, a transceiver function, a basicservice set (BSS), an extended service set (ESS), an access point, orsome other suitable terminology. The eNB 106 may provide an access pointto the EPC 110 for a UE 102. Examples of UEs 102 include a cellularphone, a smart phone, a session initiation protocol (SIP) phone, alaptop, a personal digital assistant (PDA), a satellite radio, a globalpositioning system, a multimedia device, a video device, a digital audioplayer (e.g., MP3 player), a camera, a game console, a tablet, anetbook, a smart book, an ultrabook, a drone, a robot, a sensor, amonitor, a meter, a camera/security camera, a gaming device, a wearabledevice (e.g., smart watch, smart glasses, smart ring, smart bracelet,smart wrist band, smart jewelry, smart clothing, etc.), any othersimilar functioning device, etc. The UE 102 may also be referred to bythose skilled in the art as a mobile station, a subscriber station, amobile unit, a subscriber unit, a wireless unit, a remote unit, a mobiledevice, a wireless device, a wireless communications device, a remotedevice, a mobile subscriber station, an access terminal, a mobileterminal, a wireless terminal, a remote terminal, a handset, a useragent, a mobile client, a client, or some other suitable terminology.

The eNB 106 is connected by an S1 interface to the EPC 110. The EPC 110includes a Mobility Management Entity (MME) 112, other MMEs 114, aServing Gateway 116, and a Packet Data Network (PDN) Gateway 118. TheMME 112 is the control node that processes the signaling between the UE102 and the EPC 110. Generally, the MME 112 provides bearer andconnection management. All user IP packets are transferred through theServing Gateway 116, which itself is connected to the PDN Gateway 118.The PDN Gateway 118 provides UE IP address allocation as well as otherfunctions. The PDN Gateway 118 is connected to the Operator's IPServices 122. The Operator's IP Services 122 may include, for example,the Internet, the Intranet, an IP Multimedia Subsystem (IMS), and a PS(packet-switched) Streaming Service (PSS). In this manner, the UE 102may be coupled to the PDN through the network.

In certain aspects, the UE 102 may initiate a control plane servicerequest in order to send data to the network. In some cases, the MME 112may determine that the network is overloaded and may decide to return adata back-off timer to the UE 102 via a non-access stratum (NAS)message. For example, the UE 102 may indicate to the MME 112, via theeNB 106, that no further UL or DL data transmissions are expected. Inthis case, the MME 112 may process (integrity check/decipher/forward)the received data packet, and send a service accept message to the UE102 with a back-off timer. The UE 102 may interpret the service acceptmessage as a successful transmission of the data packet, and start theback-off timer.

In certain aspects, the UE 102 may indicate to the MME 112 that furtherdata transmission is expected, and thus, the MME 112 may not process thereceived control plane data packet and may send a service reject messageto the UE 102 with a back-off timer. In this case, the UE 102 mayinterpret the service reject message as an indication that the datapacket transmission was unsuccessful.

FIG. 2 is a diagram illustrating an example of an access network 200 inin which aspects of the present disclosure may be practiced. In thisexample, the access network 200 is divided into a number of cellularregions (cells) 202. One or more lower power class eNBs 208 may havecellular regions 210 that overlap with one or more of the cells 202. Alower power class eNB 208 may be referred to as a remote radio head(RRH). The lower power class eNB 208 may be a femto cell (e.g., home eNB(HeNB)), pico cell, or micro cell. The macro eNBs 204 are each assignedto a respective cell 202 and are configured to provide an access pointto the EPC 110 for all the UEs 206 in the cells 202. There is nocentralized controller in this example of an access network 200, but acentralized controller may be used in alternative configurations. TheeNBs 204 are responsible for all radio related functions including radiobearer control, admission control, mobility control, scheduling,security, and connectivity to the serving gateway 116. The network 200may also include one or more relays (not shown). According to oneapplication, a UE may serve as a relay.

The modulation and multiple access scheme employed by the access network200 may vary depending on the particular telecommunications standardbeing deployed. In some applications, OFDM is used on the DL and SC-FDMAis used on the UL to support both frequency division duplexing (FDD) andtime division duplexing (TDD). As those skilled in the art will readilyappreciate from the detailed description to follow, the various conceptspresented herein are well suited for certain applications. However,these concepts may be readily extended to other telecommunicationstandards employing other modulation and multiple access techniques. Byway of example, these concepts may be extended to Evolution-DataOptimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are airinterface standards promulgated by the 3rd Generation PartnershipProject 2 (3GPP2) as part of the CDMA2000 family of standards andemploys CDMA to provide broadband Internet access to mobile stations.These concepts may also be extended to Universal Terrestrial RadioAccess (UTRA) employing Wideband-CDMA (W-CDMA) and other variants ofCDMA, such as TD-SCDMA; Global System for Mobile Communications (GSM)employing TDMA; and Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, and Flash-OFDMemploying OFDMA. UTRA, E-UTRA, UMTS, LTE and GSM are described indocuments from the 3GPP organization. CDMA2000 and UMB are described indocuments from the 3GPP2 organization. The actual wireless communicationstandard and the multiple access technology employed will depend on thespecific application and the overall design constraints imposed on thesystem.

The eNBs 204 may have multiple antennas supporting MIMO technology. Theuse of MIMO technology enables the eNBs 204 to exploit the spatialdomain to support spatial multiplexing, beamforming, and transmitdiversity. Spatial multiplexing may be used to transmit differentstreams of data simultaneously on the same frequency. The data streamsmay be transmitted to a single UE 206 to increase the data rate or tomultiple UEs 206 to increase the overall system capacity. This isachieved by spatially precoding each data stream (e.g., applying ascaling of an amplitude and a phase) and then transmitting eachspatially precoded stream through multiple transmit antennas on the DL.The spatially precoded data streams arrive at the UE(s) 206 withdifferent spatial signatures, which enables each of the UE(s) 206 torecover the one or more data streams destined for that UE 206. On theUL, each UE 206 transmits a spatially precoded data stream, whichenables the eNB 204 to identify the source of each spatially precodeddata stream.

Spatial multiplexing is generally used when channel conditions are good.When channel conditions are less favorable, beamforming may be used tofocus the transmission energy in one or more directions. This may beachieved by spatially precoding the data for transmission throughmultiple antennas. To achieve good coverage at the edges of the cell, asingle stream beamforming transmission may be used in combination withtransmit diversity.

In the detailed description that follows, various aspects of an accessnetwork may be described with reference to a MIMO system supporting OFDMon the DL. OFDM is a spread-spectrum technique that modulates data overa number of subcarriers within an OFDM symbol. The subcarriers arespaced apart at precise frequencies. The spacing provides“orthogonality” that enables a receiver to recover the data from thesubcarriers. In the time domain, a guard interval (e.g., cyclic prefix)may be added to each OFDM symbol to combat inter-OFDM-symbolinterference. The UL may use SC-FDMA in the form of a DFT-spread OFDMsignal to compensate for high peak-to-average power ratio (PAPR).

In certain aspects, the UE 206 sends a control plane service requestmessage from idle mode in order to transmit data to the eNB 204. In somecases, a MME (e.g., the MME 112 of FIG. 1) may determine that thenetwork is overloaded and may decide to return a data back-off timer tothe UE 206. The UE 206 may indicate to the MME, via the eNB 204, that nofurther UL or DL data transmissions are expected. In this case, the MMEmay process (integrity check/decipher/forward) the received data packet,and send a NAS message having a service accept to the UE 206 with aback-off timer. The UE 206 may interpret the service accept message as asuccessful transmission of the data packet, and start the back-offtimer.

In certain aspects, the UE 206 may indicate to the MME that further datatransmission are expected, and thus, the MME may not process thereceived control plane data packet and may send the NAS message with aservice reject and a back-off timer. In this case, the UE may interpretthe service reject message as an indication that the data packettransmission was unsuccessful.

FIG. 3 is a diagram 300 illustrating an example of a DL frame structure.A frame (10 ms) may be divided into 10 equally sized sub-frames withindices of 0 through 9. Each sub-frame may include two consecutive timeslots. A resource grid may be used to represent two time slots, eachtime slot including a resource block. The resource grid is divided intomultiple resource elements. In some cases, a resource block contains 12consecutive subcarriers in the frequency domain and, for a normal cyclicprefix in each OFDM symbol, 7 consecutive OFDM symbols in the timedomain, or 84 resource elements. For an extended cyclic prefix, aresource block contains 6 consecutive OFDM symbols in the time domainand has 72 resource elements. Some of the resource elements, asindicated as R 302, R 304, include DL reference signals (DL-RS). TheDL-RS include Cell-specific RS (CRS) (also sometimes called common RS)302 and UE-specific RS (UE-RS) 304. UE-RS 304 are transmitted only onthe resource blocks upon which the corresponding physical DL sharedchannel (PDSCH) is mapped. The number of bits carried by each resourceelement depends on the modulation scheme. Thus, the more resource blocksthat a UE receives and the higher the modulation scheme, the higher thedata rate for the UE.

In some cases, an eNB may send a primary synchronization signal (PSS)and a secondary synchronization signal (SSS) for each cell in the eNB.The primary and secondary synchronization signals may be sent in symbolperiods 6 and 5, respectively, in each of subframes 0 and 5 of eachradio frame with the normal cyclic prefix (CP). The synchronizationsignals may be used by UEs for cell detection and acquisition. The eNBmay send a Physical Broadcast Channel (PBCH) in symbol periods 0 to 3 inslot 1 of subframe 0. The PBCH may carry certain system information.

The eNB may send a Physical Control Format Indicator Channel (PCFICH) inthe first symbol period of each subframe. The PCFICH may convey thenumber of symbol periods (M) used for control channels, where M may beequal to 1, 2 or 3 and may change from subframe to subframe. M may alsobe equal to 4 for a small system bandwidth, e.g., with less than 10resource blocks. The eNB may send a Physical HARQ Indicator Channel(PHICH) and a Physical Downlink Control Channel (PDCCH) in the first Msymbol periods of each subframe. The PHICH may carry information tosupport hybrid automatic repeat request (HARQ). The PDCCH may carryinformation on resource allocation for UEs and control information fordownlink channels. The eNB may send a Physical Downlink Shared Channel(PDSCH) in the remaining symbol periods of each subframe. The PDSCH maycarry data for UEs scheduled for data transmission on the downlink.

The eNB may send the PSS, SSS, and PBCH in the center 1.08 MHz of thesystem bandwidth used by the eNB. The eNB may send the PCFICH and PHICHacross the entire system bandwidth in each symbol period in which thesechannels are sent. The eNB may send the PDCCH to groups of UEs incertain portions of the system bandwidth. The eNB may send the PDSCH tospecific UEs in specific portions of the system bandwidth. The eNB maysend the PSS, SSS, PBCH, PCFICH, and PHICH in a broadcast manner to allUEs, may send the PDCCH in a unicast manner to specific UEs, and mayalso send the PDSCH in a unicast manner to specific UEs.

A number of resource elements may be available in each symbol period.Each resource element (RE) may cover one subcarrier in one symbol periodand may be used to send one modulation symbol, which may be a real orcomplex value. Resource elements not used for a reference signal in eachsymbol period may be arranged into resource element groups (REGs). EachREG may include four resource elements in one symbol period. The PCFICHmay occupy four REGs, which may be spaced approximately equally acrossfrequency, in symbol period 0. The PHICH may occupy three REGs, whichmay be spread across frequency, in one or more configurable symbolperiods. For example, the three REGs for the PHICH may all belong insymbol period 0 or may be spread in symbol periods 0, 1, and 2. ThePDCCH may occupy 9, 18, 36, or 72 REGs, which may be selected from theavailable REGs, in the first M symbol periods, for example. Only certaincombinations of REGs may be allowed for the PDCCH. In aspects of thepresent methods and apparatus, a subframe may include more than onePDCCH.

A UE may know the specific REGs used for the PHICH and the PCFICH. TheUE may search different combinations of REGs for the PDCCH. The numberof combinations to search is typically less than the number of allowedcombinations for the PDCCH. An eNB may send the PDCCH to the UE in anyof the combinations that the UE will search.

FIG. 4 is a diagram 400 illustrating an example of an UL framestructure. The available resource blocks for the UL may be partitionedinto a data section and a control section. The control section may beformed at the two edges of the system bandwidth and may have aconfigurable size. The resource blocks in the control section may beassigned to UEs for transmission of control information. The datasection may include all resource blocks not included in the controlsection. The UL frame structure results in the data section includingcontiguous subcarriers, which may allow a single UE to be assigned allof the contiguous subcarriers in the data section.

A UE may be assigned resource blocks 410 a, 410 b in the control sectionto transmit control information to an eNB. The UE may also be assignedresource blocks 420 a, 420 b in the data section to transmit data to theeNB. The UE may transmit control information in a physical UL controlchannel (PUCCH) on the assigned resource blocks in the control section.The UE may transmit only data or both data and control information in aphysical UL shared channel (PUSCH) on the assigned resource blocks inthe data section. A UL transmission may span both slots of a subframeand may hop across frequency.

A set of resource blocks may be used to perform initial system accessand achieve UL synchronization in a physical random access channel(PRACH) 430. The PRACH 430 carries a random sequence and cannot carryany UL data/signaling. Each random access preamble occupies a bandwidthcorresponding to six consecutive resource blocks. The starting frequencyis specified by the network. That is, the transmission of the randomaccess preamble is restricted to certain time and frequency resources.There is no frequency hopping for the PRACH. The PRACH attempt iscarried in a single subframe (1 ms) or in a sequence of few contiguoussubframes and a UE can make only a single PRACH attempt per frame (10ms).

FIG. 5 is a diagram 500 illustrating an example of a radio protocolarchitecture for the user and control planes. The radio protocolarchitecture for the UE and the eNB is shown with three layers: Layer 1,Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer andimplements various physical layer signal processing functions. The L1layer will be referred to herein as the physical layer 506. Layer 2 (L2layer) 508 is above the physical layer 506 and is responsible for thelink between the UE and eNB over the physical layer 506.

In the user plane, the L2 layer 508 includes a media access control(MAC) sublayer 510, a radio link control (RLC) sublayer 512, and apacket data convergence protocol (PDCP) 514 sublayer, which areterminated at the eNB on the network side. Although not shown, the UEmay have several upper layers above the L2 layer 508 including a networklayer (e.g., IP layer) that is terminated at the PDN gateway 118 on thenetwork side, and an application layer that is terminated at the otherend of the connection (e.g., far end UE, server, etc.).

The PDCP sublayer 514 provides multiplexing between different radiobearers and logical channels. The PDCP sublayer 514 also provides headercompression for upper layer data packets to reduce radio transmissionoverhead, security by ciphering the data packets, and handover supportfor UEs between eNBs. The RLC sublayer 512 provides segmentation andreassembly of upper layer data packets, retransmission of lost datapackets, and reordering of data packets to compensate for out-of-orderreception due to hybrid automatic repeat request (HARQ). The MACsublayer 510 provides multiplexing between logical and transportchannels. The MAC sublayer 510 is also responsible for allocating thevarious radio resources (e.g., resource blocks) in one cell among theUEs. The MAC sublayer 510 is also responsible for HARQ operations.

In the control plane, the radio protocol architecture for the UE and eNBis substantially the same for the physical layer 506 and the L2 layer508 with the exception that there is no header compression function forthe control plane. The control plane also includes a radio resourcecontrol (RRC) sublayer 516 in Layer 3 (L3 layer). The RRC sublayer 516is responsible for obtaining radio resources (i.e., radio bearers) andfor configuring the lower layers using RRC signaling between the eNB andthe UE.

FIG. 6 is a block diagram of an eNB 610 in communication with a UE 650in an access network, in which aspects of the present disclosure may bepracticed. In certain aspects, the UE 650 may correspond to the UE 102of FIG. 1 and the eNB 610 may correspond to the eNB 106 of FIG. 1. Incertain aspects, a UE (e.g., UE 650) combines pairs of antenna ports togenerate at least first and second combined antenna ports. For eachcombined port, the UE adds reference signals received on ResourceElements (REs) of each of the combined pair of antenna ports. The UEthen determines channel estimates for each combined antenna port basedon the added reference signals for the combined port. In certainaspects, for each of the combined ports, the UE processes data receivedon data REs in pairs, based on the determined channel estimates of thecombined port.

In certain aspects, a Base Station (BS) (e.g., eNB 610) combines pairsof antenna ports to generate the at least first and second combinedantenna ports, for transmission in a narrow band region of a largersystem bandwidth. For each of the first and the second combined antennaports, the BS transmits same data on corresponding REs of each of thecombined pairs of antenna ports, wherein a receiving UE determineschannel estimates for each of the first and second combined ports, andprocesses the data received in the REs in pairs based on the determinedchannel estimates.

It may be noted that the UE 650 may be implemented by a combination ofone or more of the controller 659, the RX processor 656, the channelestimator 658 and/or transceiver 654 at the UE 650, for example.Further, the BS may be implemented by a combination of one or more ofthe controller 675, the TX processor and/or the transceiver 618 at theeNB 610.

In the DL, upper layer packets from the core network are provided to acontroller/processor 675. The controller/processor 675 implements thefunctionality of the L2 layer. In the DL, the controller/processor 675provides header compression, ciphering, packet segmentation andreordering, multiplexing between logical and transport channels, andradio resource allocations to the UE 650 based on various prioritymetrics. The controller/processor 675 is also responsible for HARQoperations, retransmission of lost packets, and signaling to the UE 650.

The TX processor 616 implements various signal processing functions forthe L1 layer (i.e., physical layer). The signal processing functionsincludes coding and interleaving to facilitate forward error correction(FEC) at the UE 650 and mapping to signal constellations based onvarious modulation schemes (e.g., binary phase-shift keying (BPSK),quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK),M-quadrature amplitude modulation (M-QAM)). The coded and modulatedsymbols are then split into parallel streams. Each stream is then mappedto an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot)in the time and/or frequency domain, and then combined together using anInverse Fast Fourier Transform (IFFT) to produce a physical channelcarrying a time domain OFDM symbol stream. The OFDM stream is spatiallyprecoded to produce multiple spatial streams. Channel estimates from achannel estimator 674 may be used to determine the coding and modulationscheme, as well as for spatial processing. The channel estimate may bederived from a reference signal and/or channel condition feedbacktransmitted by the UE 650. Each spatial stream is then provided to adifferent antenna 620 via a separate transmitter 618TX. Each transmitter618TX modulates an RF carrier with a respective spatial stream fortransmission.

At the UE 650, each receiver 654RX receives a signal through itsrespective antenna 652. Each receiver 654RX recovers informationmodulated onto an RF carrier and provides the information to thereceiver (RX) processor 656. The RX processor 656 implements varioussignal processing functions of the L1 layer. The RX processor 656performs spatial processing on the information to recover any spatialstreams destined for the UE 650. If multiple spatial streams aredestined for the UE 650, they may be combined by the RX processor 656into a single OFDM symbol stream. The RX processor 656 then converts theOFDM symbol stream from the time-domain to the frequency domain using aFast Fourier Transform (FFT). The frequency domain signal comprises aseparate OFDM symbol stream for each subcarrier of the OFDM signal. Thesymbols on each subcarrier, and the reference signal, is recovered anddemodulated by determining the most likely signal constellation pointstransmitted by the eNB 610. These soft decisions may be based on channelestimates computed by the channel estimator 658. The soft decisions arethen decoded and deinterleaved to recover the data and control signalsthat were originally transmitted by the eNB 610 on the physical channel.The data and control signals are then provided to thecontroller/processor 659.

The controller/processor 659 implements the L2 layer. Thecontroller/processor can be associated with a memory 660 that storesprogram codes and data. The memory 660 may be referred to as acomputer-readable medium. In the UL, the controller/processor 659provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover upper layer packets from the core network. The upper layerpackets are then provided to a data sink 662, which represents all theprotocol layers above the L2 layer. Various control signals may also beprovided to the data sink 662 for L3 processing. Thecontroller/processor 659 is also responsible for error detection usingan acknowledgement (ACK) and/or negative acknowledgement (NACK) protocolto support HARQ operations.

In the UL, a data source 667 is used to provide upper layer packets tothe controller/processor 659. The data source 667 represents allprotocol layers above the L2 layer. Similar to the functionalitydescribed in connection with the DL transmission by the eNB 610, thecontroller/processor 659 implements the L2 layer for the user plane andthe control plane by providing header compression, ciphering, packetsegmentation and reordering, and multiplexing between logical andtransport channels based on radio resource allocations by the eNB 610.The controller/processor 659 is also responsible for HARQ operations,retransmission of lost packets, and signaling to the eNB 610.

Channel estimates derived by a channel estimator 658 from a referencesignal or feedback transmitted by the eNB 610 may be used by the TXprocessor 668 to select the appropriate coding and modulation schemes,and to facilitate spatial processing. The spatial streams generated bythe TX processor 668 are provided to different antenna 652 via separatetransmitters 654TX. Each transmitter 654TX modulates an RF carrier witha respective spatial stream for transmission.

The UL transmission is processed at the eNB 610 in a manner similar tothat described in connection with the receiver function at the UE 650.Each receiver 618RX receives a signal through its respective antenna620. Each receiver 618RX recovers information modulated onto an RFcarrier and provides the information to a RX processor 670. The RXprocessor 670 may implement the L1 layer.

The controller/processor 675 implements the L2 layer. Thecontroller/processor 675 can be associated with a memory 676 that storesprogram codes and data. The memory 676 may be referred to as acomputer-readable medium. In the UL, the controller/processor 675provides demultiplexing between transport and logical channels, packetreassembly, deciphering, header decompression, control signal processingto recover upper layer packets from the UE 650. Upper layer packets fromthe controller/processor 675 may be provided to the core network. Thecontroller/processor 675 is also responsible for error detection usingan ACK and/or NACK protocol to support HARQ operations. Thecontrollers/processors 675, 659 may direct the operations at the eNB 610and the UE 650, respectively.

The controller/processor 659 and/or other processors, components and/ormodules at the UE 650 may perform or direct operations, for example,operations 800 in FIG. 8, and/or other processes for the techniquesdescribed herein for implementing the new transmission scheme. Further,the controller/processor 675 and/or other processors, components and/ormodules at the eNB 610 may perform or direct operations, for example,operations 900 in FIG. 9, and/or other processes for the techniquesdescribed herein for implementing the new transmission scheme. Incertain aspects, one or more of any of the components shown in FIG. 6may be employed to perform example operations 800 and 900, and/or otherprocesses for the techniques described herein. The memories 660 and 676may store data and program codes for the UE 650 and eNB 610respectively, accessible and executable by one or more other components(e.g., the controllers/processors 675, 659) of the UE 650 and the eNB610.

In certain aspects, the UE 650 send a control plane service requestmessage 680 from idle mode in order to transmit data to the eNB 610. Insome cases, a MME (e.g., the MME 112 of FIG. 1) may determine that thenetwork is overloaded and may decide to return a data back-off timer tothe UE 650. In certain aspects, the UE 650 may indicate to the MME, viathe eNB 610, that no further UL or DL data transmissions are expected.In this case, the MME may process (integrity check/decipher/forward) thereceived data packet, and send a NAS message 682 having a service acceptto the UE 650 with a back-off timer. The UE 650 may interpret theservice accept message as a successful transmission of the data packet,and start the back-off timer.

In certain aspects, the UE 650 may indicate to the MME that further datatransmission are expected, and thus, the MME may not process thereceived control plane data packet and may send the NAS message 682 witha service reject and a back-off timer. In this case, the UE mayinterpret the service reject message as an indication that the datapacket transmission was unsuccessful.

Internet-of-Things

The Internet-of-Things (IoT) is a network of physical objects or“things” embedded with, for example, electronics, software, sensors, andnetwork connectivity (e.g., wireless, wireline, positioning, etc.),which enable these objects to collect and exchange data. IoT allowsobjects to be sensed and controlled remotely across existing networkinfrastructure, creating opportunities for more direct integrationbetween the physical world and computer-based systems, and resulting inimproved efficiency, accuracy and economic benefit. When IoT isaugmented with sensors and actuators, the technology becomes an instanceof the more general class of cyber-physical systems, which alsoencompasses technologies such as smart grids, smart homes, intelligenttransportation and smart cities. Each “thing” is generally uniquelyidentifiable through its embedded computing system but is able tointeroperate within the existing Internet infrastructure.

Example Techniques for Processing a Data Packet Received Over ControlPlane in Congestion Scenario

In the context of internet of things (IOT), downlink (DL)/uplink (UL) ofdata packets may be communicated via control plane (CP) signaling (e.g.,data over non-access stratum (NAS) between a UE and MME). In certainaspects, the MME (e.g., MME 112 of FIG. 1) may identify that it is in acongestion scenario. For example, the MME may determine that the networkused for communication is congested. The MME may also receive an UL datapacket over control plane signaling from the UE. Due to the congestionscenario, the MME may decide to either process or discard the datapacket from the UE. In some cases, the UE may further provideinformation with regards to whether further messages (downlink (DL) oruplink (UL)) or data packets are expected from this communication. TheMME may decide to process a received message (packet) since it alreadyreceived it. However, if the message is likely to trigger more messages,e.g. an ACK from the application server, then the MME may decide todiscard the message.

In some cases, a back-off timer may be provided by the MME to the UE.The back-off timer may indicate a time period during which the UE maydefer data transmissions to the MME. In some cases, the UE may send aservice request message with EPS session management (ESM) data transportwith the data packet. Then, the overloaded MME may send a service acceptwith a data back-off timer. However, it may be unclear to the UE whetherthe MME has processed the received data packet and forwarded it to thecorrect core network (CN) node (i.e. the Service Capability ExposureFunction (SCEF) or SGW).

In certain aspects, if the MME sends a service accept to the UE, the UEmay assume that the MME has correctly processed and forwarded the datapacket (e.g. CP data packet) sent by the UE. However, this may createissues for the case that a UL data packet sent by the UE would trigger amessage response (e.g. an ACK) from the application server or triggers astream of further message exchanges. Since the MME's intention is tostop data transport for the UE, in the case when further messageexchanges may be possible for the UE, it may be better for the MME toreject the service request and drop any data packets contained in it. Inthat case, the MME can send a service reject message including a databack-off timer to the UE. The UE may interpret this indication as anunsuccessful transmission of the data packet. The unsuccessfultransmission of the data may be indicated to upper layers (e.g.,application layer) of the UE.

In certain aspects of the present disclosure, the UE may indicate to theMME, in a release assistance information (RAI) in a NAS protocol dataunit (PDU), that no further UL or DL data transmissions are expected. Inthat case, since the MME already received the data packet and determinesthat no further packets are expected based on the indication from theUE, the MME may process and forward the data packet to the CN, in whichcase the MME may send a service accept with a data back-off timer. Incertain aspects of the present disclosure, if the MME sends a serviceaccept with a data back-off timer during the service request procedure,the MME also processes and forwards the data packet received in theservice request message.

FIG. 7 illustrates example operations 700 for communicating controlplane data back-off timer at registration, in accordance with certainaspects of the present disclosure. For example, at step 1, the UE maysend an attach or tracking area update (TAU) request to the MME. Thepreferred network behavior may be control plane cellular IoT (CIoT)optimization. The MME may then determine whether a back-off timer is tobe sent to the UE. For example, the MME may determine that the networkis overloaded and a back-off timer should be sent to the UE. At step 2,if the MME is overloaded or close to overload (based on operator setthreshold or policy) with data transfer via the control plane, it mayaccept the registration request (e.g., the attach/TAU request) from theUE, but may return a control plane data back-off timer via theattach/TAU accept message, indicating a time for which the UE shoulddefer data transmissions. At this point, the UE may start the back-offtimer.

FIG. 8 illustrates example operations 800 for wireless communication, inaccordance with certain aspects of the present disclosure. The operation800 may be performed, for example, by an MME, such as the MME 112 ofFIG. 1.

The operations 800, begin at block 802, by receiving a messagecomprising a data packet from a user equipment (UE) during acommunication session. At block 804, the MME may detect whether the datapacket is the last data packet for transmission or reception by the UEduring the communication session. For example, in some cases, the MMEmay receive an indication from the UE indicating whether the data packetis the last data packet. In other cases, the UE may not send theindication of whether the data packet is the last data packet, and thelack of indication from the UE may indicate to the MME that the datapacket is the last data packet. In otherwords, the UE may only providean indication, to the MME, of whether the data packet is the last datapacket during the communication session.

At block 806, the operations 800 continue by the MME determining whetherto process or discard the data packet based on the detection and whethera backoff timer is to be sent to the UE. For example, the MME may detectwhether a network used to receive the data packet is overloaded. Atblock 808, the MME may process or discard the data packet based on thedetermination at block 806. For example, the MME may discard the datapacket if it is determined that the data packet is not the last datapacket, or process the data packet otherwise.

In some cases, the MME may receive a service request (e.g., CP servicerequest) with the data packet (e.g., a CP data packet). As describedabove, the MME may determine to send an indication of a data back-offtimer to the UE. If the UE indicates (e.g., in a release assistanceinformation (RAI) in the NAS protocol data unit (PDU)) that no furtherUL or DL data transmissions are expected (e.g., that the data packet isthe last data packet for transmission or reception), then the MME mayprocess (integrity check/decipher/forward to another network node) thereceived data packet, and send service accept message to the UE with thedata back-off timer. In this case, the UE may interpret reception of theservice accept message as a successful transmission of the data packet(e.g., that the MME processed the data packet). For other cases, (e.g.no RAI or RAI with further DL expected), the MME may not process thedata packet and send a service reject message to the UE with databack-off timer. The UE may interpret the service reject message as anunsuccessful transmission of the data packet.

FIG. 9 illustrates example operations 900 for wireless communication, inaccordance with certain aspects of the present disclosure. The operation900 may be performed, for example, by a UE, such as the UE 102 of FIG.1.

The operations 900, begin at block 902, by transmitting a data packet toa network node (e.g., MME 112) during a communication session. At block904, the UE may receive a message including an indication of a back-offtimer from the network node in response to the data packet. At block906, the UE may determine whether the data packet was processed by thenetwork node based on whether the message comprises an accept message ora reject message. At block 908, the UE may indicate to an upper layer(e.g., the application layer) of the UE whether the data packet wasprocessed based on the determination.

In certain aspects, the UE may move the communication session to a userplane of the UE based on the message. For example, the UE may performNAS procedure to request the network node (e.g., MME 112) to enable datacommunication over data radio bearers (DRBs), i.e., user plane. This canbe done by performing a registration update (e.g., TAU) with datapending indication or regular service request procedure to enable DRBs.The registration update triggers the MME to request the radio accessnode (e.g., eNB) to establish DRBs for all PDN connections allowed to beserved over DRBs, including the PDN connections where data communicationwas previously served over CP path. The MME also establishes S 1-Utunneling between SGW and the eNB for user plane data transport. Oncethe DRBs for the PDN connections are established between the UE and theradio access node, the UE starts data communication over the user plane,i.e. over DRBs plus S 1-U.

As presented above, the UE may receive a back-off timer from the networknode. In certain aspects of the present disclosure, if the UE receives adata packet (e.g., mobile terminated (MT) CP data packet) while the databack-off timer is running, the UE may stop the back-off timer andcontinue with data transmissions. For example, the MME may send a databack-off timer to the UE while overloaded, however, the MME may stopbeing overloaded before back-off timer expires. Thus, the MME mayreceive an MT data for the UE, and since the MME is not overloadedanymore, the MME may proceed with delivering data packet to the UE. Inthis case, the UE can take the receipt of the data packet as anindication that the MME is not overloaded, and thus, stop the back offtimer.

If the UE is prevented from sending any data during a back-off timer,several issues may arise. In some cases, the application server, whensending an MT data packet, would be expecting a response message fromthe UE (e.g. an ACK). However, if the UE is not allowed to transmit theACK, then the message transaction may fail at the application layer.Moreover, if the MME is no longer congested, then there may be no reasonto prevent the UE from sending mobile originated (MO) data (even dataother than the ACK for the MT data). In certain aspects of the presentdisclosure, when the UE receives MT data from the MME, while the databack-off timer is running, then the UE may stop the back-off timer.

FIG. 10 illustrates operations 1000 for communicating control planeservice request and control plane data back-off timer, in accordancewith certain aspects of the present disclosure. At step 1, the UEinitiates control plane service request from idle mode in order totransmit data (e.g., via control plane CIoT EPS optimization). If theMME is overloaded or close to overload (based on operator set thresholdor policy) with data transfer via the control plane, the MME may decideto return a data back-off timer to the UE. For example, if the UE hasadditionally indicated in a RAI in the NAS PDU that no further UL or DLdata transmissions are expected, then the MME may process (integritycheck/decipher/forward) the received data packet, and send a serviceaccept message to the UE with a back-off timer. In this case, the UE mayinterpret the service accept message as a successful transmission of thedata packet, and start the back-off timer.

For other cases such as when the UE has indicated to the MME thatfurther data transmission are expected, the MME may not process thereceived control plane data packet and may send a service reject messageto the UE with a back-off timer. In this case, the UE may interpret theservice reject message as an indication that the data packettransmission was unsuccessfully (e.g., was not processed by the MME). Atthis point, the UE may start the back-off timer. In certain aspects, theMME may take into consideration whether the PDN connection for thecommunication session is set to control plane only to make the decisionof whether to reject the data packet and send the service reject messageor move the PDN connection to a user plane and process the data packet.

In certain aspects, while the back-off timer is running, the UE may notsend any NAS messages to the MME if a NAS data PDU with user data isincluded (i.e., data transfer via Control Plane CIoT EPS Optimization).However, there are a few exceptions. For example, if the UE isconfigured as a low priority device and allowed to send exceptionreporting, the UE may initiate control plane service request forexception reporting even if the back-off timer is running. If the UEreceives a NAS message (e.g. service accept or service reject) with aback-off timer in response to exception reporting, the UE may no longersend any exception reporting while the back-off timer is running.Moreover, as presented above, if the UE receives MT data while theback-off timer is running, the UE may stop the back-off timer.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

In some cases, rather than actually transmitting a frame, a device mayhave an interface to output a frame for transmission. For example, aprocessor may output a frame, via a bus interface, to an RF front endfor transmission. Similarly, rather than actually receiving a frame, adevice may have an interface to obtain a frame received from anotherdevice. For example, a processor may obtain (or receive) a frame, via abus interface, from an RF front end for transmission.

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

For example, means for moving, means for determining, means formonitoring, means for deferring, means for processing, means forindicating, and/or means for including, may comprise a processingsystem, which may include one or more processors, such as the TXprocessor 616, transmitter(s) 618, and/or the controller/processor 675of the eNB 610 illustrated in FIG. 6, and/or the TX processor 668, thetransmitter(s) 654, and/or the controller/processor 659 of the userequipment 650 illustrated in FIG. 6. Means for transmitting and/or meansfor sending may comprise a transmitter, which may include TX processor616, transmitter(s) 618, and/or the antenna(s) 620 of the eNB 610illustrated in FIG. 6, and/or the TX processor 668, the transmitter(s)654, and/or the antenna(s) 652 of the user equipment 650 illustrated inFIG. 6. Means for receiving may comprise a receiver, which may includeRX processor 670, receiver(s) 618, and/or the antenna(s) 620 of the eNB610 illustrated in FIG. 6, and/or the RX processor 656, the receiver(s)654, and/or the antenna(s) 652 of the user equipment 650 illustrated inFIG. 6.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a wirelessnode, a user interface (e.g., keypad, display, mouse, joystick, etc.)may also be connected to the bus. The bus may also link various othercircuits such as timing sources, peripherals, voltage regulators, powermanagement circuits, and the like, which are well known in the art, andtherefore, will not be described any further. The processor may beimplemented with one or more general-purpose and/or special-purposeprocessors. Examples include microprocessors, microcontrollers, DSPprocessors, and other circuitry that can execute software. Those skilledin the art will recognize how best to implement the describedfunctionality for the processing system depending on the particularapplication and the overall design constraints imposed on the overallsystem.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer-readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, phasechange memory, ROM (Read Only Memory), PROM (Programmable Read-OnlyMemory), EPROM (Erasable Programmable Read-Only Memory), EEPROM(Electrically Erasable Programmable Read-Only Memory), registers,magnetic disks, optical disks, hard drives, or any other suitablestorage medium, or any combination thereof. The machine-readable mediamay be embodied in a computer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a wireless node and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a wirelessnode and/or base station can obtain the various methods upon coupling orproviding the storage means to the device. Moreover, any other suitabletechnique for providing the methods and techniques described herein to adevice can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. A method for wireless communication by auser-equipment (UE), comprising: transmitting a communication to anetwork node during a communication session, the communicationcomprising a data packet and an indication of whether the data packet isa final data packet for transmission or reception by the UE during thecommunication session; receiving a message including an indication of aback-off timer from the network node in response to the data packet;determining whether the data packet was processed by the network nodebased on whether the message comprises an accept message or a rejectmessage, wherein whether the message comprises an accept message or areject message is based at least on the indication of whether the datapacket is the final data packet for transmission or reception by the UEduring the communication session; and indicating to an upper layer ofthe UE whether the data packet was processed based on the determination.2. The method of claim 1, further comprising moving the communicationsession to a user plane of the UE based on the message.
 3. The method ofclaim 2, further comprising: determining to defer the moving of thecommunication session to the user plane if the message comprises aservice accept message, wherein the service accept message indicatesthat the data packet was processed by the network node; and deferringthe moving of the communication session based on the determination. 4.The method of claim 3, further comprising: determining that another datapacket is pending for transmission to the network node, whereindeferring the moving of the communication session comprises moving thecommunication session upon the determination that the other data packetis pending for transmission.
 5. The method of claim 1, furthercomprising: receiving a data packet from the network node while theback-off timer is running; and stopping the back-off timer in responseto the reception of the data packet.
 6. The method of claim 5, whereinthe received data packet comprises a mobile terminated (MT) data packet.7. An apparatus for wireless communication by a user equipment (UE),comprising: means for transmitting a communication to a network nodeduring a communication session, the communication comprising a datapacket and an indication of whether the data packet is a final datapacket for transmission or reception by the UE during the communicationsession; means for receiving a message including an indication of aback-off timer from the network node in response to the data packet;means for determining whether the data packet was processed by thenetwork node based on whether the message comprises an accept message ora reject message, wherein whether the message comprises an acceptmessage or a reject message is based at least on the indication ofwhether the data packet is the final data packet for transmission orreception by the UE during the communication session; and means forindicating to an upper layer of the UE whether the data packet wasprocessed based on the determination.
 8. An apparatus for wirelesscommunication by a user equipment (UE), comprising: at least oneprocessor; a memory coupled to the at least one processor and storinginstructions, when executed by the processor cause the apparatus to:transmit a communication to a network node during a communicationsession, the communication comprising a data packet and an indication ofwhether the data packet is a final data packet for transmission orreception by the UE during the communication session; receive a messageincluding an indication of a back-off timer from the network node inresponse to the data packet; determine whether the data packet wasprocessed by the network node based on whether the message comprises anaccept message or a reject message, wherein whether the messagecomprises an accept message or a reject message is based at least on theindication of whether the data packet is the final data packet fortransmission or reception by the UE during the communication session;and indicate to an upper layer of the UE whether the data packet wasprocessed based on the determination.
 9. The apparatus of claim 8,wherein the instructions are executable by the at least one processor tocause the apparatus to move the communication session to a user plane ofthe UE based on the message.
 10. The apparatus of claim 9, wherein theinstructions are executable by the at least one processor to cause theapparatus to: determine to defer moving of the communication session tothe user plane if the message comprises a service accept message,wherein the service accept message indicates that the data packet wasprocessed by the network node; and defer moving of the communicationsession based on the determination.
 11. The apparatus of claim 10,wherein the instructions are executable by the at least one processor tocause the apparatus to: determine that another data packet is pendingfor transmission to the network node; and defer moving of thecommunication session by moving the communication session upon thedetermination that the other data packet is pending for transmission.12. The apparatus of claim 8, wherein the instructions are executable bythe at least one processor to cause the apparatus to: receive a datapacket from the network node while the back-off timer is running; andstop the back-off timer in response to the reception of the data packet.13. The apparatus of claim 12, wherein the received data packetcomprises a mobile terminated (MT) data packet.
 14. A non-transitorycomputer readable medium for wireless communication by a user equipment(UE), the non-transitory computer readable medium having stored thereonprogram code for causing the UE to: transmit a communication to anetwork node during a communication session, the communicationcomprising a data packet and an indication of whether the data packet isa final data packet for transmission or reception by the UE during thecommunication session; receive a message including an indication of aback-off timer from the network node in response to the data packet;determine whether the data packet was processed by the network nodebased on whether the message comprises an accept message or a rejectmessage, wherein whether the message comprises an accept message or areject message is based at least on the indication of whether the datapacket is the final data packet for transmission or reception by the UEduring the communication session; and indicate to an upper layer of theUE whether the data packet was processed based on the determination.